201597921 has 36 divisors (see below), whose sum is σ = 348199488. Its totient is φ = 109894752.

The previous prime is 201597901. The next prime is 201597931. The reversal of 201597921 is 129795102.

It is not a de Polignac number, because 201597921 - 2¹⁴ = 201581537 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201597901) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 540291 + ... + 540663.

It is an arithmetic number, because the mean of its divisors is an integer number (9672208).

Almost surely, 2^201597921 is an apocalyptic number.

201597921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

201597921 is a deficient number, since it is larger than the sum of its proper divisors (146601567).

201597921 is an equidigital number, since it uses as much as digits as its factorization.

201597921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 36.

The square root of 201597921 is about 14198.5182677630. The cubic root of 201597921 is about 586.3568679357.

The spelling of 201597921 in words is "two hundred one million, five hundred ninety-seven thousand, nine hundred twenty-one".